Field of Disclosure
The present disclosure relates to a photodetecting device and use thereof, and more particularly, to a photodetecting device and a method of using the same for photo detection.
Description of Related Art
A photosensor (also called as photodetector) is one of the most common elements used in the modern electronic products, such as digital cameras, light sensors and photocounters. The photosensor is a sensor that uses a photosensitive element to convert light signals ma electrical signals, and the common photosensitive element includes, for example, a photodiode, photoconductor and a junction photodiode. The photoconductor is mainly a semiconductor material, which has ohmic contacts at the two terminals thereof; when incident light irradiates the surface of the semiconductor, electron-hole pairs are generated, causing the conductivity to increase, and the photoelectric current (Iph) increases accordingly. For the photodiode, the photons irradiate to the diode depletion region, and the electron-hole pairs generated thereby undergo opposite potentials of the two terminals, such that the electrons and the holes are separated and move, thus forming photoelectric current phenomenon; if a current amplifier is integrated externally, the photoelectric current can be correctly measured, and the current and the number of absorbed photons can be evaluated. The main design purpose of the junction photodiode is to be used for optical communications and to use the energy gap difference of different materials, such as indium phosphide (InP) and indium gallium arsenide (InGaAs), to separate the electron-hole pairs generated by the light energy, and to allow the electrons to move toward the n+ terminal to become a photoelectric current.
However, because the characteristics of the photodiode is often limited by the material selected during the fabricating process, different photosensors often need to be selected to perform photo detection. In practice, most applications need to use different photosensors to perform experiments. For example, when photosensors are used to perform a bioluminescence reaction experiment, a photosensor with high sensitivity and a photosensor with wide optical waveband are both needed to perform the experiment. However, the photosensor with high sensitivity results in signal saturation easily when operated for observation of normal light source, while when the photosensor with normal sensitivity is used to observe weak luminescence reaction, it often needs to extend the exposure time and integral time of the photosensor for obtaining required information. However, many experimental results also indicate that the measured signals are all noise data due to over-adjusted exposure time or integral time. As for the current technology, the effect is achieved via external optical design or installing another component, such as a photomultiplier tube. However, such device often requires larger experimental space and environment, thus having certain limitations for experimental implementation.
Therefore, a photodetecting device currently needs to be developed, which can adjust various parameters itself, so as to improve the sensitivity thereof and further achieve multifarious application fields.